Reducing plywood tearout

mickyd · Post by **mickyd** » Thu Jan 28, 2010 9:43 pm

JPG40504 wrote:Like any other potentially hazardous endeavor .....

BTW Do we all understand why reverse/shallow cuts reduce tearout?

Angle of attack pushes microscopic tearout up into cut vs. pulling it out??

heathicus · Post by **heathicus** » Fri Jan 29, 2010 12:12 pm

The initial reverse/scoring cut cuts into the wood so the surrounding wood acts as support to reduce tearout. For the full cut, although the blade is cutting out of the wood, or as MickyD stated, pulling the fibers away from the wood, the fibers on the bottom face aren't there to be pulled on. As the blade exits the wood, there is still wood to the side of the blade to support the fibers. So both cuts are done in such a way that provides support to the surrounding fibers so they are held in place instead of being torn out.

JPG · Post by **JPG** » Fri Jan 29, 2010 3:38 pm

The Direction the teeth are moving as they exit the workpiece. With a shallow cut the teeth are moving near horizontal(not pulling down on the edge of the cut[leading edge and side edge]). With a reverse cut, the teeth are pulling only against the edge of the cut as it exits(there is no 'trailing' edge of the workpiece). They can still grab if feed is not in line.

Just off the boaticus - What part of the open area of the blade slot 'supports' the edge? You are correct re its already cut so no tear(unless feed is not in line again).